Hemodynamic Effects of Propranolol on Canine Cardiovascular System under Variable Concentration of Insoflurane Anesthesia

Kim, Chong Sung; Kim, Yong Lack

Abstract

To determine the beta-sympatheitc activity of isoflurane and interaction between isoflurane and propranolol the study on cardiovascular effects in 8 dogs under various concentration of isoflurane anesthesia after intravenous injection of propranolol was undertaken. Heart rate, mean arterial pressure, central venous pressure, pumonary artery pressure, pulmonary capillary wedge pressure, and cardiac output were monitored and recorded under N2O-O2. N2O-O2-1 MAC of isoflurane, and N2O-O2-2 MCA of isofiurane, respectively and than at 20 minutes after wash;out with N2O-O2,and at 20 minutes after propranolol injection, and at 20 minute after the same conditioned anesthesia, above parameters were rechecked, respectively. Using above paramethers the cardiac index, stroke volume index, left ventricular stroke work index, systemic vascular resistance and pulmonry vascular resistance were calculated. Following results were obtained by comparing each data, and between isoflurane alone and isoflur- ane with propranolol injection.1) The heart rate, mean arterial pressure, cardiac output, cardiac index, left ventricular stroke index, systemic vascular resistance decreased significantly according to increment of isoflurane concentration. 2) The heart rate, mean arterial pressure, cardiac output, cardiac index and left ventricular stroke work index decreased significantly after injection of propranolol comparing with the data before injection and under same concentraion of isoflurane decreased significantly in the dogs pretreated with propranolol. 3) The stroke volume index did not change significantly with injection of propranolol but as adding isoflurane decreased significantly according to the concentration of isoflurane. 4) The pulmonary artery pressure did not change significantly with injection of propranolol but as adding isoflurane increased significantly comparing with that under the same concentration of isoflur-ane without propranolol. 5) The central venous pressure did not change significantly according to injection of propranolol or adding isoflurane. 6) The systemic vascular resistance and pulmonary vascular resistance increased significantly with injection of propranolol and adding isoflurane.